net/ip/tinydtls/examples/contiki/dtls-server.c - third_party/github/zephyrproject-rtos/zephyr - Git at Google

 /*
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. Neither the name of the Institute nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
  * This file is part of the Contiki operating system.
  *
  */

 #include "contiki.h"
 #include "contiki-lib.h"
 #include "contiki-net.h"

 #if UIP_CONF_IPV6_RPL
 #include "contiki/rpl/rpl.h"
 #endif /* UIP_CONF_IPV6_RPL */

 #include <string.h>

 #include "tinydtls.h"

 #ifndef DEBUG
 #define DEBUG DEBUG_PRINT
 #endif
 #include "contiki/ip/uip-debug.h"

 #include "debug.h"
 #include "dtls.h"

 #ifdef ENABLE_POWERTRACE
 #include "powertrace.h"
 #endif

 #define UIP_IP_BUF   ((struct uip_ip_hdr *)&uip_buf[UIP_LLH_LEN])
 #define UIP_UDP_BUF  ((struct uip_udp_hdr *)&uip_buf[UIP_LLIPH_LEN])

 #define MAX_PAYLOAD_LEN 120

 static struct uip_udp_conn *server_conn;

 static dtls_context_t *dtls_context;

 static const unsigned char ecdsa_priv_key[] = {
 			0xD9, 0xE2, 0x70, 0x7A, 0x72, 0xDA, 0x6A, 0x05,
 			0x04, 0x99, 0x5C, 0x86, 0xED, 0xDB, 0xE3, 0xEF,
 			0xC7, 0xF1, 0xCD, 0x74, 0x83, 0x8F, 0x75, 0x70,
 			0xC8, 0x07, 0x2D, 0x0A, 0x76, 0x26, 0x1B, 0xD4};

 static const unsigned char ecdsa_pub_key_x[] = {
 			0xD0, 0x55, 0xEE, 0x14, 0x08, 0x4D, 0x6E, 0x06,
 			0x15, 0x59, 0x9D, 0xB5, 0x83, 0x91, 0x3E, 0x4A,
 			0x3E, 0x45, 0x26, 0xA2, 0x70, 0x4D, 0x61, 0xF2,
 			0x7A, 0x4C, 0xCF, 0xBA, 0x97, 0x58, 0xEF, 0x9A};

 static const unsigned char ecdsa_pub_key_y[] = {
 			0xB4, 0x18, 0xB6, 0x4A, 0xFE, 0x80, 0x30, 0xDA,
 			0x1D, 0xDC, 0xF4, 0xF4, 0x2E, 0x2F, 0x26, 0x31,
 			0xD0, 0x43, 0xB1, 0xFB, 0x03, 0xE2, 0x2F, 0x4D,
 			0x17, 0xDE, 0x43, 0xF9, 0xF9, 0xAD, 0xEE, 0x70};

 static int
 read_from_peer(struct dtls_context_t *ctx,
 	       session_t *session, uint8 *data, size_t len) {
   size_t i;
   for (i = 0; i < len; i++)
     PRINTF("%c", data[i]);

   /* echo incoming application data */
   dtls_write(ctx, session, data, len);
   return 0;
 }

 static int
 send_to_peer(struct dtls_context_t *ctx,
 	     session_t *session, uint8 *data, size_t len) {

   struct uip_udp_conn *conn = (struct uip_udp_conn *)dtls_get_app_data(ctx);

   uip_ipaddr_copy(&conn->ripaddr, &session->addr);
   conn->rport = session->port;

   PRINTF("send to ");
   PRINT6ADDR(&conn->ripaddr);
   PRINTF(":%u\n", uip_ntohs(conn->rport));

   uip_udp_packet_send(conn, data, len);

   /* Restore server connection to allow data from any node */
   memset(&conn->ripaddr, 0, sizeof(conn->ripaddr));
   memset(&conn->rport, 0, sizeof(conn->rport));

   return len;
 }

 #ifdef DTLS_PSK
 /* This function is the "key store" for tinyDTLS. It is called to
  * retrieve a key for the given identity within this particular
  * session. */
 static int
 get_psk_info(struct dtls_context_t *ctx, const session_t *session,
 	     dtls_credentials_type_t type,
 	     const unsigned char *id, size_t id_len,
 	     unsigned char *result, size_t result_length) {

   struct keymap_t {
     unsigned char *id;
     size_t id_length;
     unsigned char *key;
     size_t key_length;
   } psk[3] = {
     { (unsigned char *)"Client_identity", 15,
       (unsigned char *)"secretPSK", 9 },
     { (unsigned char *)"default identity", 16,
       (unsigned char *)"\x11\x22\x33", 3 },
     { (unsigned char *)"\0", 2,
       (unsigned char *)"", 1 }
   };

   if (type != DTLS_PSK_KEY) {
     return 0;
   }

   if (id) {
     int i;
     for (i = 0; i < sizeof(psk)/sizeof(struct keymap_t); i++) {
       if (id_len == psk[i].id_length && memcmp(id, psk[i].id, id_len) == 0) {
 	if (result_length < psk[i].key_length) {
 	  dtls_warn("buffer too small for PSK");
 	  return dtls_alert_fatal_create(DTLS_ALERT_INTERNAL_ERROR);
 	}

 	memcpy(result, psk[i].key, psk[i].key_length);
 	return psk[i].key_length;
       }
     }
   }

   return dtls_alert_fatal_create(DTLS_ALERT_DECRYPT_ERROR);
 }
 #endif /* DTLS_PSK */

 #ifdef DTLS_ECC
 static int
 get_ecdsa_key(struct dtls_context_t *ctx,
 	      const session_t *session,
 	      const dtls_ecdsa_key_t **result) {
   static const dtls_ecdsa_key_t ecdsa_key = {
     .curve = DTLS_ECDH_CURVE_SECP256R1,
     .priv_key = ecdsa_priv_key,
     .pub_key_x = ecdsa_pub_key_x,
     .pub_key_y = ecdsa_pub_key_y
   };

   *result = &ecdsa_key;
   return 0;
 }

 static int
 verify_ecdsa_key(struct dtls_context_t *ctx,
 		 const session_t *session,
 		 const unsigned char *other_pub_x,
 		 const unsigned char *other_pub_y,
 		 size_t key_size) {
   return 0;
 }
 #endif /* DTLS_ECC */

 PROCESS(udp_server_process, "UDP server process");
 AUTOSTART_PROCESSES(&udp_server_process);
 /*---------------------------------------------------------------------------*/
 static void
 dtls_handle_read(dtls_context_t *ctx) {
   session_t session;

   if(uip_newdata()) {
     uip_ipaddr_copy(&session.addr, &UIP_IP_BUF->srcipaddr);
     session.port = UIP_UDP_BUF->srcport;
     session.size = sizeof(session.addr) + sizeof(session.port);

     dtls_handle_message(ctx, &session, uip_appdata, uip_datalen());
   }
 }
 /*---------------------------------------------------------------------------*/
 static void
 print_local_addresses(void)
 {
   int i;
   uint8_t state;

   PRINTF("Server IPv6 addresses: \n");
   for(i = 0; i < UIP_DS6_ADDR_NB; i++) {
     state = uip_ds6_if.addr_list[i].state;
     if(uip_ds6_if.addr_list[i].isused &&
        (state == ADDR_TENTATIVE || state == ADDR_PREFERRED)) {
       PRINT6ADDR(&uip_ds6_if.addr_list[i].ipaddr);
       PRINTF("\n");
     }
   }
 }

 #if 0
 static void
 create_rpl_dag(uip_ipaddr_t *ipaddr)
 {
   struct uip_ds6_addr *root_if;

   root_if = uip_ds6_addr_lookup(ipaddr);
   if(root_if != NULL) {
     rpl_dag_t *dag;
     uip_ipaddr_t prefix;

     rpl_set_root(RPL_DEFAULT_INSTANCE, ipaddr);
     dag = rpl_get_any_dag();
     uip_ip6addr(&prefix, 0xaaaa, 0, 0, 0, 0, 0, 0, 0);
     rpl_set_prefix(dag, &prefix, 64);
     PRINTF("created a new RPL dag\n");
   } else {
     PRINTF("failed to create a new RPL DAG\n");
   }
 }
 #endif

 void
 init_dtls() {
   static dtls_handler_t cb = {
     .write = send_to_peer,
     .read  = read_from_peer,
     .event = NULL,
 #ifdef DTLS_PSK
     .get_psk_info = get_psk_info,
 #endif /* DTLS_PSK */
 #ifdef DTLS_ECC
     .get_ecdsa_key = get_ecdsa_key,
     .verify_ecdsa_key = verify_ecdsa_key
 #endif /* DTLS_ECC */
   };
 #if 0
   uip_ipaddr_t ipaddr;
   /* struct uip_ds6_addr *root_if; */
 #endif /* UIP_CONF_ROUTER */

   PRINTF("DTLS server started\n");

 #if 0  /* TEST */
   memset(&tmp_addr, 0, sizeof(rimeaddr_t));
   if(get_eui64_from_eeprom(tmp_addr.u8));
 #if NETSTACK_CONF_WITH_IPV6
   memcpy(&uip_lladdr.addr, &tmp_addr.u8, 8);
 #endif
 #endif /* TEST */

 #if 0
 /*   uip_ip6addr(&ipaddr, 0xaaaa, 0, 0, 0, 0, 0, 0, 0); */
 /*   uip_ds6_set_addr_iid(&ipaddr, &uip_lladdr); */
 /*   uip_ds6_addr_add(&ipaddr, 0, ADDR_AUTOCONF); */

 /*   create_rpl_dag(&ipaddr); */
 /* #else */
   /* uip_ds6_addr_add(&ipaddr, 0, ADDR_AUTOCONF); */

   uip_ip6addr(&ipaddr, 0xaaaa, 0,0,0,0x0200,0,0,0x0003);
   uip_ds6_addr_add(&ipaddr, 0, ADDR_MANUAL);

   create_rpl_dag(&ipaddr);
 #endif /* UIP_CONF_ROUTER */

   server_conn = udp_new(NULL, 0, NULL);
   udp_bind(server_conn, UIP_HTONS(20220));

   dtls_set_log_level(DTLS_LOG_DEBUG);

   dtls_context = dtls_new_context(server_conn);
   if (dtls_context)
     dtls_set_handler(dtls_context, &cb);
 }

 /*---------------------------------------------------------------------------*/
 PROCESS_THREAD(udp_server_process, ev, data)
 {
   PROCESS_BEGIN();

   dtls_init();
   init_dtls();

   print_local_addresses();

   if (!dtls_context) {
     dtls_emerg("cannot create context\n");
     PROCESS_EXIT();
   }

 #ifdef ENABLE_POWERTRACE
   powertrace_start(CLOCK_SECOND * 2);
 #endif

   while(1) {
     PROCESS_WAIT_EVENT();
     if(ev == tcpip_event) {
       dtls_handle_read(dtls_context);
     }
 #if 0
     if (bytes_read > 0) {
       /* dtls_handle_message(dtls_context, &the_session, readbuf, bytes_read); */
       read_from_peer(dtls_context, &the_session, readbuf, bytes_read);
     }
     dtls_handle_message(ctx, &session, uip_appdata, bytes_read);
 #endif
   }

   PROCESS_END();
 }
 /*---------------------------------------------------------------------------*/
	/*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	* 3. Neither the name of the Institute nor the names of its contributors
	* may be used to endorse or promote products derived from this software
	* without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	* SUCH DAMAGE.
	*
	* This file is part of the Contiki operating system.
	*
	*/

	#include "contiki.h"
	#include "contiki-lib.h"
	#include "contiki-net.h"

	#if UIP_CONF_IPV6_RPL
	#include "contiki/rpl/rpl.h"
	#endif /* UIP_CONF_IPV6_RPL */

	#include <string.h>

	#include "tinydtls.h"

	#ifndef DEBUG
	#define DEBUG DEBUG_PRINT
	#endif
	#include "contiki/ip/uip-debug.h"

	#include "debug.h"
	#include "dtls.h"

	#ifdef ENABLE_POWERTRACE
	#include "powertrace.h"
	#endif

	#define UIP_IP_BUF ((struct uip_ip_hdr *)&uip_buf[UIP_LLH_LEN])
	#define UIP_UDP_BUF ((struct uip_udp_hdr *)&uip_buf[UIP_LLIPH_LEN])

	#define MAX_PAYLOAD_LEN 120

	static struct uip_udp_conn *server_conn;

	static dtls_context_t *dtls_context;

	static const unsigned char ecdsa_priv_key[] = {
	0xD9, 0xE2, 0x70, 0x7A, 0x72, 0xDA, 0x6A, 0x05,
	0x04, 0x99, 0x5C, 0x86, 0xED, 0xDB, 0xE3, 0xEF,
	0xC7, 0xF1, 0xCD, 0x74, 0x83, 0x8F, 0x75, 0x70,
	0xC8, 0x07, 0x2D, 0x0A, 0x76, 0x26, 0x1B, 0xD4};

	static const unsigned char ecdsa_pub_key_x[] = {
	0xD0, 0x55, 0xEE, 0x14, 0x08, 0x4D, 0x6E, 0x06,
	0x15, 0x59, 0x9D, 0xB5, 0x83, 0x91, 0x3E, 0x4A,
	0x3E, 0x45, 0x26, 0xA2, 0x70, 0x4D, 0x61, 0xF2,
	0x7A, 0x4C, 0xCF, 0xBA, 0x97, 0x58, 0xEF, 0x9A};

	static const unsigned char ecdsa_pub_key_y[] = {
	0xB4, 0x18, 0xB6, 0x4A, 0xFE, 0x80, 0x30, 0xDA,
	0x1D, 0xDC, 0xF4, 0xF4, 0x2E, 0x2F, 0x26, 0x31,
	0xD0, 0x43, 0xB1, 0xFB, 0x03, 0xE2, 0x2F, 0x4D,
	0x17, 0xDE, 0x43, 0xF9, 0xF9, 0xAD, 0xEE, 0x70};

	static int
	read_from_peer(struct dtls_context_t *ctx,
	session_t session, uint8 data, size_t len) {
	size_t i;
	for (i = 0; i < len; i++)
	PRINTF("%c", data[i]);

	/* echo incoming application data */
	dtls_write(ctx, session, data, len);
	return 0;
	}

	static int
	send_to_peer(struct dtls_context_t *ctx,
	session_t session, uint8 data, size_t len) {

	struct uip_udp_conn conn = (struct uip_udp_conn )dtls_get_app_data(ctx);

	uip_ipaddr_copy(&conn->ripaddr, &session->addr);
	conn->rport = session->port;

	PRINTF("send to ");
	PRINT6ADDR(&conn->ripaddr);
	PRINTF(":%u\n", uip_ntohs(conn->rport));

	uip_udp_packet_send(conn, data, len);

	/* Restore server connection to allow data from any node */
	memset(&conn->ripaddr, 0, sizeof(conn->ripaddr));
	memset(&conn->rport, 0, sizeof(conn->rport));

	return len;
	}

	#ifdef DTLS_PSK
	/* This function is the "key store" for tinyDTLS. It is called to
	* retrieve a key for the given identity within this particular
	* session. */
	static int
	get_psk_info(struct dtls_context_t ctx, const session_t session,
	dtls_credentials_type_t type,
	const unsigned char *id, size_t id_len,
	unsigned char *result, size_t result_length) {

	struct keymap_t {
	unsigned char *id;
	size_t id_length;
	unsigned char *key;
	size_t key_length;
	} psk[3] = {
	{ (unsigned char *)"Client_identity", 15,
	(unsigned char *)"secretPSK", 9 },
	{ (unsigned char *)"default identity", 16,
	(unsigned char *)"\x11\x22\x33", 3 },
	{ (unsigned char *)"\0", 2,
	(unsigned char *)"", 1 }
	};

	if (type != DTLS_PSK_KEY) {
	return 0;
	}

	if (id) {
	int i;
	for (i = 0; i < sizeof(psk)/sizeof(struct keymap_t); i++) {
	if (id_len == psk[i].id_length && memcmp(id, psk[i].id, id_len) == 0) {
	if (result_length < psk[i].key_length) {
	dtls_warn("buffer too small for PSK");
	return dtls_alert_fatal_create(DTLS_ALERT_INTERNAL_ERROR);
	}

	memcpy(result, psk[i].key, psk[i].key_length);
	return psk[i].key_length;
	}
	}
	}

	return dtls_alert_fatal_create(DTLS_ALERT_DECRYPT_ERROR);
	}
	#endif /* DTLS_PSK */

	#ifdef DTLS_ECC
	static int
	get_ecdsa_key(struct dtls_context_t *ctx,
	const session_t *session,
	const dtls_ecdsa_key_t **result) {
	static const dtls_ecdsa_key_t ecdsa_key = {
	.curve = DTLS_ECDH_CURVE_SECP256R1,
	.priv_key = ecdsa_priv_key,
	.pub_key_x = ecdsa_pub_key_x,
	.pub_key_y = ecdsa_pub_key_y
	};

	*result = &ecdsa_key;
	return 0;
	}

	static int
	verify_ecdsa_key(struct dtls_context_t *ctx,
	const session_t *session,
	const unsigned char *other_pub_x,
	const unsigned char *other_pub_y,
	size_t key_size) {
	return 0;
	}
	#endif /* DTLS_ECC */

	PROCESS(udp_server_process, "UDP server process");
	AUTOSTART_PROCESSES(&udp_server_process);
	/---------------------------------------------------------------------------/
	static void
	dtls_handle_read(dtls_context_t *ctx) {
	session_t session;

	if(uip_newdata()) {
	uip_ipaddr_copy(&session.addr, &UIP_IP_BUF->srcipaddr);
	session.port = UIP_UDP_BUF->srcport;
	session.size = sizeof(session.addr) + sizeof(session.port);

	dtls_handle_message(ctx, &session, uip_appdata, uip_datalen());
	}
	}
	/---------------------------------------------------------------------------/
	static void
	print_local_addresses(void)
	{
	int i;
	uint8_t state;

	PRINTF("Server IPv6 addresses: \n");
	for(i = 0; i < UIP_DS6_ADDR_NB; i++) {
	state = uip_ds6_if.addr_list[i].state;
	if(uip_ds6_if.addr_list[i].isused &&
	(state == ADDR_TENTATIVE \|\| state == ADDR_PREFERRED)) {
	PRINT6ADDR(&uip_ds6_if.addr_list[i].ipaddr);
	PRINTF("\n");
	}
	}
	}

	#if 0
	static void
	create_rpl_dag(uip_ipaddr_t *ipaddr)
	{
	struct uip_ds6_addr *root_if;

	root_if = uip_ds6_addr_lookup(ipaddr);
	if(root_if != NULL) {
	rpl_dag_t *dag;
	uip_ipaddr_t prefix;

	rpl_set_root(RPL_DEFAULT_INSTANCE, ipaddr);
	dag = rpl_get_any_dag();
	uip_ip6addr(&prefix, 0xaaaa, 0, 0, 0, 0, 0, 0, 0);
	rpl_set_prefix(dag, &prefix, 64);
	PRINTF("created a new RPL dag\n");
	} else {
	PRINTF("failed to create a new RPL DAG\n");
	}
	}
	#endif

	void
	init_dtls() {
	static dtls_handler_t cb = {
	.write = send_to_peer,
	.read = read_from_peer,
	.event = NULL,
	#ifdef DTLS_PSK
	.get_psk_info = get_psk_info,
	#endif /* DTLS_PSK */
	#ifdef DTLS_ECC
	.get_ecdsa_key = get_ecdsa_key,
	.verify_ecdsa_key = verify_ecdsa_key
	#endif /* DTLS_ECC */
	};
	#if 0
	uip_ipaddr_t ipaddr;
	/* struct uip_ds6_addr root_if; /
	#endif /* UIP_CONF_ROUTER */

	PRINTF("DTLS server started\n");

	#if 0 /* TEST */
	memset(&tmp_addr, 0, sizeof(rimeaddr_t));
	if(get_eui64_from_eeprom(tmp_addr.u8));
	#if NETSTACK_CONF_WITH_IPV6
	memcpy(&uip_lladdr.addr, &tmp_addr.u8, 8);
	#endif
	#endif /* TEST */

	#if 0
	/* uip_ip6addr(&ipaddr, 0xaaaa, 0, 0, 0, 0, 0, 0, 0); */
	/* uip_ds6_set_addr_iid(&ipaddr, &uip_lladdr); */
	/* uip_ds6_addr_add(&ipaddr, 0, ADDR_AUTOCONF); */

	/* create_rpl_dag(&ipaddr); */
	/* #else */
	/* uip_ds6_addr_add(&ipaddr, 0, ADDR_AUTOCONF); */

	uip_ip6addr(&ipaddr, 0xaaaa, 0,0,0,0x0200,0,0,0x0003);
	uip_ds6_addr_add(&ipaddr, 0, ADDR_MANUAL);

	create_rpl_dag(&ipaddr);
	#endif /* UIP_CONF_ROUTER */

	server_conn = udp_new(NULL, 0, NULL);
	udp_bind(server_conn, UIP_HTONS(20220));

	dtls_set_log_level(DTLS_LOG_DEBUG);

	dtls_context = dtls_new_context(server_conn);
	if (dtls_context)
	dtls_set_handler(dtls_context, &cb);
	}

	/---------------------------------------------------------------------------/
	PROCESS_THREAD(udp_server_process, ev, data)
	{
	PROCESS_BEGIN();

	dtls_init();
	init_dtls();

	print_local_addresses();

	if (!dtls_context) {
	dtls_emerg("cannot create context\n");
	PROCESS_EXIT();
	}

	#ifdef ENABLE_POWERTRACE
	powertrace_start(CLOCK_SECOND * 2);
	#endif

	while(1) {
	PROCESS_WAIT_EVENT();
	if(ev == tcpip_event) {
	dtls_handle_read(dtls_context);
	}
	#if 0
	if (bytes_read > 0) {
	/* dtls_handle_message(dtls_context, &the_session, readbuf, bytes_read); */
	read_from_peer(dtls_context, &the_session, readbuf, bytes_read);
	}
	dtls_handle_message(ctx, &session, uip_appdata, bytes_read);
	#endif
	}

	PROCESS_END();
	}
	/---------------------------------------------------------------------------/